Why, you're very welcome, Kanga.
3 seconds sound clip from The New Adventures of Winnie the Pooh - Tigger is the Mother of Invention / The Bug Stops Here (S3E8).
You can hear this line at 00:11:23.800 in the Blu-ray version of the TV Series.
Quote context
[...]
- So it's oblivious what I got to do next.
- It is?
- I'm gonna invent another invention.
- It'll be stupendious, colossical, and did I mention monumentous?
- Oh, my.
- It'll be so incredibibble, so unbelievabibble, why, even I won't believe it. Hoo hoo hoo hoo hoo!
- Thank you, Pooh. Oh, it's so very nice of you to go out of your way to help us.
- Why, you're very welcome, Kanga.
- But exactly where is it I'm going?
- Why, you're not going anywhere, Pooh. You're babysitting the boys while Owl and I go somewhere.
- Why do they call it babysitting? We're not babies.
- It reminds me of the time...
- Hoo, yes. The care of children is life's most important task.
[...]